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View Full Version : G752VT CPU reaching 100 C after re-paste?!



drummerdimitri
01-08-2016, 06:00 PM
So I've decided to re-paste my CPU and GPU like I do with all my new computers since they usually do a crappy job and/or don't use the best thermal paste and got a temperature drop of 4 C on my GPU during the Furmark stress test but for some reason the CPU is getting much hotter even though I remember having applied a good quantity to it so now one of the four cores goes to 100C if not more while the others are in the 90's and one of them stay cool in the high 70's.

What could be causing this? The computer is perfectly stable even though the CPU temps are very high.

Is it worth re-pasting the CPU just to make sure I didn't screw up?

Dreamonic
01-08-2016, 10:21 PM
Is the CPU fan working?

Did you plug it back in during reassembly?

How much thermal paste did you apply and what method?
When you said "good quantity" I feel you've applied too much already.

Using the dot method where the line method should be used would cause temperature variances between each individual core on a rectangular die. Due to the spread coverage of your applied method when the heatsink is compressing it during installation, with the amount of paste you used will determine that factor.

A little goes a long way when applying thermal paste as you know and if you want very consistent core temperatures, then I'd recommend the very thinly applied "smooth spread" method. This can greatly reduce the temperature variations between core temperatures because of the spread coverage. Regardless of what you see online, try different methods yourself and you'll notice one method in particular stands out as netting you the best temperatures overall.

drummerdimitri
01-09-2016, 12:54 AM
Yes, both fans are working.

I used the line method on the CPU since it is rectangular in shape and applied an average amount of thermal paste.

I've decided not to re-paste the CPU as long as my computer is stable and not crashing because every time I get in there I risk damaging the motherboard and it's not really worth the risk on a new laptop.

I will just re-apply if there comes a day when the system starts crashing during games due to an overheated CPU till then I am using the computer normally.

Googlegot
04-06-2016, 05:05 AM
You've opened up a real can of worms with this one. A friend of mine and I each bought a g752vl at the same time (same cooler) and he re-pasted his system and had the same problem.

Don't worry, though, as I was able to fix his issue with the steps below:

Unfortunately, you're going to have to disassemble your laptop again.

Parts needed:
1. Phillips P1 screwdriver (I assume you have this already)
2. Copper GPU 'shims', .5mm, or 1mm if you can't find .5mm (look on amazon)
3. More thermal paste
4. Alcohol for cleaning the last application
5. q-tips for cleaning
6. Booze for celebration afterward

Steps:
1. Disassemble the laptop and remove the heatsink from the motherboard (you've done this before, I'm not going to list the steps again unless you need them)
2. Clean up any previous paste you put in there
3. Clean the copper shim with alcohol
4. Apply thermal paste evenly across one side of the shim, then place it where the CPU goes on the heatsink
5. Place the heatsink on the motherboard, and screw in the GPU screws in the order indicated on the heatsink engravings (clockwise starting with top left) - DO NOT SCREW IN THE CPU SCREWS YET
6. Inspect the placement of the heatsink and shim, if it is not in complete contact with the CPU, remove it and go to step 7 - Use a bright flashlight and bring the board to eye level to check
7. If the heatsink/shim is not in complete flat contact with the CPU, remove the heatsink, then GENTLY - I cannot stress this enough - GENTLY bend the heat pipes between the CPU and GPU coolers to bring it level with the CPU
8. Repeat 5-7 until the heatsink is even with both the CPU and GPU dies, screwing it only into the GPU as reference
9. Remove the heatsink, apply thermal paste, and reassemble the laptop

If you followed the steps correctly, your temps should be ~70-75c max GPU and ~90-92C max CPU (when stressing both CPU and GPU simultaneously). If you do not achieve these results, you may have to repeat this process again. It took me 3 tries to get it right.

I specialize in laptop repair, but this has been the most difficult system to repaste with good results I've ever had to work with. Be careful, and you'll get yourself out of this bind like I did. I will not be reapplying paste to my personal g752vl.